This invention relates to antennas and more particularly to an improved deployable log periodic VEE antenna especially adaptable for space craft where compactness, reliability and resistance to thermal distortion is important.
Deployable antennas are well known in the art. Typical examples thereof are shown in the U.S. patents to Mirrione et al. U.S. Pat. No. 3,950,758, to Carr U.S. Pat. No. 3,213,415, to Barbano, et al. U.S. Pat. No. 3,500,424, and to Esposito, et al. U.S. Pat. No. 3,715,759.
The Mirrione et al. antenna uses self locking hinges intermediate the ends the mast and the antenna elements for folding of the antenna primarily for the purpose of convenient boxing. This antenna is heavy being directed to the home and commercial market.
The Carr antenna has its antenna elements connected at the ends by pins for collapsing and expanding the antenna in a zigzag fashion. This antenna is utilizable in commercial television, and like the Mirrione et al. antenna, is generally unsuitable for space craft.
The Barbano et al. antenna is formed of a flexible sheet to permit folding for storage and the Eposito et al. antenna is similar but uses an inflatable spherical enclosure to unfurl the antenna elements.
Also, there are numerous patents teaching log periodic principles in a design of antennas, one such patent for example, is the U.S. patent to Cory et al. U.S. Pat. No. 3,697,999. However, none of the foregoing have the concept of utilizing low expansion material in a log periodic antenna whereby dimensional stability is obtained over a large temperature range so as to be useful in space craft, nor do they show an antenna capable of being easily collapsed into a small configuration for transportation purposes and yet reliably deployed when desired, by a means which also gives rigidity to the deployed antenna.
Accordingly, it is a primary object of this invention to provide a log periodic antenna configuration utilizing low expansion material so that dimensional stability is obtained over a large temperature range so as to be particularly useful in space craft and which can be collapsed into a small compact configuration and reliably deployed.